IWC Da Vinci Perpetual Stainless Steel IW3750-29

IWC presented the Da Vinci Perpetual, reference 3750, at the Basel fair in 1985. Kurt Klaus's perpetual calendar mechanism, built from 81 components, sits on an automatic chronograph based on the Valjoux 7750 and shows a four-digit year accurate until 2499. Hanno Burtscher designed the case, with its articulated lugs.

The steel black-dial watch also came in German (IW3750-28), English (IW3750-30) and French (IW3750-31), and on a bracelet as the Italian IW3750-33. The steel IW3750-12 is the same Italian watch with a white dial, and the IW3750-24 puts the black dial in red gold. The 39 mm case is 14.3 mm thick, has an acrylic crystal and takes a 19 mm strap.